Little Mallow (Cheeseweed)

What is little mallow?

Little mallow is an upright, fast-growing weed in the same family as cotton, okra and hibiscus. Most people call it cheeseweed after its fruit, a flat button that splits into wedges like a tiny wheel of cheese. Little mallow (cheeseweed) identification starts with that fruit and the round, palm-lobed leaves; separating it from its cousin common mallow is the last step of little mallow identification, and it comes down to the petals and the texture of the fruit.

It is a problem because it grows fast and gets tough. Seedlings form a strong taproot early, which soon turns woody and makes older plants hard to pull, and the herbicides most homeowners can buy do little to it. Unchecked, plants become bushes several feet tall that crowd vegetables and flowers, jam harvest equipment in farm fields, and shelter whiteflies, thrips and plant viruses such as tomato spotted wilt and tomato yellow leaf curl.

Little Mallow identification: what to look for

Look at a flower and a fruit side by side. Little mallow's petals barely extend past the green sepals behind them, and its cheese-wheel fruit has a wrinkled surface. Common mallow's petals are about twice as long as its sepals, and its fruit is smooth.

• Seedlings: Distinctly heart-shaped, hairless, long-stalked seed leaves. The first true leaf is almost round; later leaves are weakly lobed with wavy, toothed edges and a red spot at the base.
• Leaves: Alternate, roughly round and palm-like, with five to seven shallow lobes and round-toothed margins; hairiness varies.
• Stems: Tough, woody and mostly upright, often taller than 2 1/2 feet, giving older plants a bushy look.
• Flowers: About 2/5 inch across, white to pale pink, clustered at the bases of the leaf stalks, with petals about as long as the sepals.
• Fruit and seeds: A flattened, wedge-sectioned fruit with a wrinkled surface; each section holds one reddish-brown, kidney-shaped seed.
• Roots: A deep, tough taproot that is hard to remove even on fairly young plants.

Where it grows in the United States

Little mallow is a widespread weed in California, where UC IPM reports it statewide up to about 4,900 feet, except possibly in the Great Basin. USDA lists it as introduced in the lower 48 states, Hawaii and Canada, and Kew's Plants of the World Online notes that it has become an almost worldwide weed. Outside California, University of Arizona vegetable specialists report that it survives year-round in their region and copes with compacted clay or sand, freezing nights and high heat. In Florida, UF/IFAS records it in scattered counties from the Panhandle to Orange and Sarasota counties, but does not rate it a problem in the state's natural areas.

It is not fussy about where it grows as long as the ground has been disturbed: vegetable gardens, new landscapes, orchards, vineyards, crop fields, roadsides and vacant lots. Because its hard-coated seeds sprout a few at a time over many years, a bed you cleared once can keep producing seedlings season after season.

Little Mallow look-alikes

A few plants get mixed up with it:

• Common mallow (Malva neglecta): Very similar leaves and the same cheese-wheel fruit, but it spreads low, reaching about 2 feet. Its petals are notched and about twice as long as the sepals, and its fruit is smooth rather than wrinkled.
• Bristly mallow (Modiola caroliniana): A low, bristly-haired perennial whose prostrate stems root where they touch the ground. Its leaves are coarsely toothed and often deeply lobed, its single flowers are orange to dull violet-red, and each fruit section carries two hornlike beaks.

How to get rid of little mallow

Pulling, digging and mowing: Hoe or pull young plants, ideally at four true leaves or fewer, before the taproot becomes woody. Cutting young plants at the crown can kill them, but older plants may resprout. For many small seedlings, shallow cultivation works if the blade or tines pull them out or cut the taproot below the soil surface. Mowing does not work, because buds below mower height regrow, and neither solarization nor flaming is effective.

Cultural control matters most, because the right conditions keep it from coming back.

• Mulch beds with at least 3 inches of bark or wood chips and keep it at that depth so seedlings cannot push through.
• Plant competitive, desirable plants that shade the soil and cut germination.
• Remove plants before they set seed to shrink the seed bank over time.
• Keep mallows out of and around vegetable gardens, since they can harbor whiteflies, thrips and plant viruses.

Herbicides: Chemical control is weak. UC IPM reports no effective herbicides for home use. In turf, products containing 2,4-D give limited control of young plants; use them only in lawns, since 2,4-D injures any broadleaf plant it touches. Mallow is one of the few weeds glyphosate does not control well. In agricultural settings, oryzalin or pendimethalin applied before seeds germinate can give partial control, though uneven germination makes timing hard. Use only products labeled for your site and follow the label exactly. The label is the law. If you hire someone to spray, make sure they hold your state’s pesticide applicator license; the rules for each state are in our pesticide applicator license guide.

Keeping it from coming back

Stop seed production. Little mallow reproduces only by seed, and its hard-coated seeds stay alive in the soil for years, so every plant you remove before it fruits pays off for seasons to come.

Keep beds mulched and planted, and check gardens soon after the first fall rains, when new seedlings appear and are easiest to pull.

Questions we get about little mallow

Similar weeds

Common MallowMalva neglectaAnnual SowthistleSonchus oleraceusBermuda ButtercupOxalis pes-caprae